"""Shared paths and constants for the seti_meta study."""
import os
import numpy as np

HERE = os.path.dirname(os.path.abspath(__file__))
STUDY = os.path.dirname(HERE)
DATA = os.path.join(STUDY, "data")
FIGS = os.path.join(STUDY, "figures")
RAW = os.environ.get("SETI_META_RAW", "fermi_raw/seti_meta")
for _d in (DATA, FIGS, RAW, os.path.join(RAW, "vizier")):
    os.makedirs(_d, exist_ok=True)

PC = 3.0856775814913673e16  # m
FOURPI = 4.0 * np.pi

# Reference powers (W)
L_ARECIBO = 2.0e13       # Arecibo S-band planetary radar EIRP (Ekers et al. 2002; Sheikh et al. 2025)
L_KI = 1.74e17           # Kardashev I: sunlight intercepted by Earth
L_KII = 3.83e26          # Kardashev II: solar luminosity
L_LTE = 4.0e9            # peak LTE mobile-tower leakage (Saide et al. 2023), ~20 MHz wide, NOT narrowband

# EIRP grid used everywhere (W)
LGRID = np.logspace(8.0, 28.5, 165)   # 0.125 dex steps


def eirp_min(d_pc, smin_wm2):
    """Minimum detectable isotropic power (W) at distance d (pc) for flux threshold smin (W/m^2)."""
    return FOURPI * (np.asarray(d_pc) * PC) ** 2 * smin_wm2


def dmax_pc(L, smin_wm2):
    """Maximum distance (pc) at which EIRP L (W) is above flux threshold smin (W/m^2)."""
    return np.sqrt(np.asarray(L) / (FOURPI * smin_wm2)) / PC